66.91Apply it to “Mack the Knife”

This is enormously practical.

For the walking-swing version:

LH walks.

RH melody stays clear.

Between phrases, use guide-tone fills rather than arbitrary scales.

For a later reharmonized chorus:

preserve smooth 3rd/7th lines even as you add tritone substitutions and secondary dominants.

That keeps the arrangement sounding polished instead of harmonically busy.